【作者】 徐文总；

【导师】 胡源；

【作者基本信息】 中国科学技术大学 ， 安全科学与工程， 2014， 博士

【摘要】 聚氨酯弹性体具有优异的耐磨、耐油、耐撕裂、耐化学腐蚀等特性,广泛应用于工农业生产、国防建设和我们的日常生活当中,但普通的聚氨酯材料容易燃烧、阻燃性能差：另外,聚酯型的聚氨酯还容易水解,不耐水、表面性能差,限制了聚氨酯材料在实际中的应用,因此,提高聚氨酯材料的阻燃性和耐水性具有重大的意义。在文献查阅的基础上,本文主要从二个方面着手,对聚氨酯弹性体进行改性,以提高它的阻燃、疏水的性能：(1)从聚氨酯的硬段出发,利用分子设计,合成四种新型的二胺类扩链剂,把功能性的元素F、P、S、Br等引入到聚氨酯弹性体中,合成出在本质上具有疏水阻燃特性的聚氨酯弹性体；(2)合成一种含氟含磷含氮的低聚物膨胀型阻燃剂,并将其应用到热塑性聚氨酯弹性体中。利用红外光谱和核磁共振谱仪对合成的化合物结构进行表征,利用热失重分析仪、微型燃烧量热仪、接触角仪、扫描电镜等对聚氨酯弹性体的性能进行了一系列研究,另外,对聚氨酯的固化反应和热降解反应动力学进行了研究。通过研究,揭示了合成的聚氨酯弹性体结构和性能之间的关系,在理论和实践方面都具有创新意义。主要的研究内容和结果如下：1.通过FT-IR、1HNMR、19F NMR、31PNMR的研究结果,分析表明,合成的四种二元胺：2,2-二[4-(4-氨基-2-三氟甲基苯氧基)苯基]六氟丙烷(BAFPF6P)、10-[2,5-二(2-三氟甲基-4-氨基苯氧基)苯基]-9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPQ-NH2)、1,4-二[(4-氨基-2-三氟甲基苯氧基)-3,5-二溴苯基]丙烷(BAFBP)、4,4’-二(4-氨基-2-三氟甲基苯氧基)二苯基砜(BAFPPS),化学结构与预期设计的一致。2.用合成的四种二元胺代替3,3’-二氯-4,4’-二氨基二苯基甲烷(MOCA)作为扩链剂,并通过改变异氰酸酯指数、聚酯二元醇的分子量等,分别成功地制备出含氟、含氟含磷、含氟含硫、含氟含溴的聚氨酯弹性体。3.通过接触角测试结果表明,由于氟元素的引入,新制备的四种聚氨酯弹性体与普通的聚氨酯弹性体相比表面张力都有所下降,但下降的程度有所不同,以2,2-二[4-(4-氨基-2-三氟甲基苯氧基)苯基]六氟丙烷(BAFPF6P)为扩链剂制备的含氟聚氨酯弹性体与水的接触角最大,达到105.5。,表面张力下降幅度达到近50%,效果明显；同时吸水率实验也进一步证实,含氟聚氨酯的疏水性提高、吸水率降低。4.MCC的试验结果表明,新制备的四种聚氨酯弹性体与普通的聚氨酯弹性体相比热释放速率和总的热释放量都下降,由于所引入的元素不一样,起阻燃作用的机理是不同的,效果也不一样。含氟含磷聚氨酯弹性体的残碳量最高,最大达到27.7%；含氟含溴聚氨酯弹性体的最大热释放速率、热释放总量最小,最大热释放速率最小的只有102W/g,热释放总量最小的仅为5.9J/g,远远低于普通聚氨酯弹性体。5.TGA的测试结果表明,合成的四种含氟聚氨酯弹性体耐热性能表现不同,以2,2-二[4-(4-氨基-2-三氟甲基苯氧基)苯基]六氟丙烷(BAFPF6P)为扩链剂制备的弹性体耐热性能要高于普通的聚氨酯弹性体,但以10-[2,5-二(2-三氟甲基-4-氨基苯氧基)苯基]9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPQ-NH2)为扩链剂制备的聚氨酯弹性体耐热性能要低于普通的聚氨酯弹性体,这主要可能是由于其中含有易于断裂的P-O键的缘故。6.通过二氯磷酸苯酯(PDCP)与含氟二胺反应成功地合成了一种含氟含磷含氮的低聚物膨胀型阻燃剂,并在热塑性聚氨酯弹性体中(TPU)进行了应用研究,结果表明其效果优于常用的阻燃剂聚磷酸胺(APP),在TPU中添加30份时,氧指数达到30%,按照ASTM UL94标准测试能达到V0级,同时,易于成型,具有良好的加工性能。7.用橡胶硫化／树脂固化仪对聚氨酯的固化动力学进行研究,结果表明含氟聚氨酯固化时的表观活化达到71.6KJ/mol,而以MOCA为固化剂的聚氨酯固化时的表观活化能仅为41.6KJ/mol。分析认为,可能是由于BAFPF6P分子中-CF3基团的影响,使得-NH2与-NCO基团亲核加成反应活性降低。热降解动力学研究表明,含氟含磷聚氨酯弹性体的热降解活化能要高于普通氨酯弹性体的热降解活化能,从而也从另一方面说明了为什么含氟含磷聚氨酯弹性体的阻燃性要好于普通的聚氨酯弹性体。更多还原

【Abstract】 Due to their excellent resistance to abrasion, oil, tear, chemical corrosion and other properties, polyurethane elastomers (PUEs) have been widely applied in industrial and agricultural production, national defense construction and people’s daily life. However, ordinary polyurethane material is combustible and its flame retarding performance is poor. In addition, polyester PUEs are easy to hydrolyze. Its water resistance property and surface property are poor, which has limited the practical application of PUEs. Therefore, it is of great significance to improve the performance of PUEs regarding to flame retarding and water resistance.On the basis of related literature, this work studied the modification of PUEs mainly in two aspects to improve its flame retarding performance and hydrophobic nature:(1) four new types of diamine chain extenders were synthesized by changing the hard segments of polyurethane through molecular design. Then a kind of polyurethane elastomer that is flame retarding and hydrophobic naturally was synthesized by introducing functional elements like F, P, S, and Br into the material with the help of the diamine chain extenders.(2) A kind of oligomer expansion retardant that contains fluorine, phosphorus and nitrogen was synthesized and applied to thermoplastic polyurethane elastomers. The group characterized the structure of the synthesized compounds using FT-IR (Fourier Transform infrared spectroscopy) and NMR (nuclear magnetic resonance spectrometer). Besides, a series of investigations were conducted on the performance, curing reaction and thermal degradation reaction kinetics of the PUEs with the help of a thermo-gravimetric analyzer, a contact angle meter, a micro combustion calorimeter and SEM (scanning electron microscopy). The research revealed the relationship between the structure and properties of PUEs, which has significance for innovation in both theory and practice. The main work and results of the study are as follows:1. The results of of the analysis of FT-IR,1H NMR,19F NMR and31P NMR, the structures of the four synthetic diamines, including2,2-bis [4-(4-amino-2-trifluoromethyl phenoxy) phenyl] hexafluoropropane (BAFPF6P),10-[2,5-bis (2-trifluoromethyl-4-aminophenoxy)phenyl]-9,10-dihydro-9-oxa-10-phosphaphenanthre ne-10-oxide (DOPQ-NH2),1,4-bis [(4-amino-2-trifluoromethyl-phenoxy)-3,5-dibromo-phenyl]propane(BAFBP), and4,4’-bis (4-amino-2-trifluoromethyl-phenoxy) diphenyl sulfone (BAFPPS), were consistent with the design.2. Using the four kinds of synthetic diamines as chain extender instead of MOCA, through changing the isocyanate index and molecular weight of polyester glycol, etc., four kinds of PUEs--respectively fluorinated, fluorinated and phosphorous, fluorinated and sulphureous, fluorinated and bromie were synthesized successfully.3. Contact angle test results showed that compared with conventional ones, surface tensions of the four new kinds of PUEs decreased due to the introduction of fluorine element, but the degrees were different. The contact angle between the fluorinated PUEs with BAFPF6P as chain extender and water was the biggest, up to105.5°. The effect was obvious with the surface tension decreasing by nearly50%. Meanwhile, the water absorption test further proved that the fluorinated PUEs were more hydrophobic and had lower water absorption.4. MCC test results indicated that the heat release rate and THR (total heat release) of the four new kinds of PUEs decreased compared with conventional PUEs. Since the elements introduced were different, the mechanism of flame retarding varied, and the effect was also different. The carbon residue of the fluorinated and phosphorous PUEs was the largest, with a maximum of27.7%. The PHRR (peak heat release rate) and THR of fluorinated and bromie PUEs were the minimum, and the values were respectively102W/g and5.9J/g, far below the ordinary PUEs.5. Through TGA test, it was found that the heat resistant performance of the four kinds of fluorinated PUEs was different. The heat resistance of PUEs synthesized with BAFPF6P was higher than ordinary PUEs, while that of PUEs synthesized with DOPQ-NH2was lower. The main reason may be the existence of the easy-to-break bond of P-O.6. A kind of oligomer expansion type flame retardant containing fluorine, phosphorus and nitrogen was successfully synthesized through Phenyl dichlorophosphate (PDCP) reacting with fluorinated diamine. And the research of the retardant in thermoplastic polyurethane elastomer(TPU) showed that the performance was better than commonly used flame retardant polyphosphate amine(APP). When adding30parts of the oligomer expansion type flame retardant into the TPU, the oxygen index was up to30%, reaching the V0level when tested in accordance with the ASTM UL94standard. What’s more, the retardant was easy to mold and had good processing performance.7. Research on the curing kinetics of the PUEs by using rubber vulcanization /resin curing apparatus showed that the apparent activation energy of fluorinated polyurethane reached71.6KJ/mol during the curing reaction, while the value was only41.6KJ/mol when MOCA was used as curing agent. The analysis indicated that the-CF3group in the BAFPF6P molecule might result in the decrease of nucleophilic addition reaction activity of-NH2and-NCO groups. Thermal degradation kinetics studies showed that the thermal degradation activation energy of the fluorinated and phosphorus PUEs was higher than that of ordinary PUEs, which on the other hand explains why the fluorinated and phosphorous PUEs performed better in flame retarding compared with ordinary PUEs.更多还原